Twisted pair cables are commonly used for the wiring of computer and telephone networks. Twisted pair wire orientation is governed by EIA/TIA Standard 568B and industry connection methods.
Conventional twisted pair cable includes four twisted pair conductors inside an outer insulation jacket. In some cables a plastic cross shaped extrusion resides inside the cable jacket along with the wires to separate the four pairs from each other and maintain each pair within its own quadrant within the cable jacket.
The four twisted pairs are color coded as a blue pair, a green pair, an orange pair, and a brown pair. Each pair includes two conductors: a first conductor covered by solid color insulation colored to match that pair designation and a second conductor covered by white insulation with colored stripes that are the same color as the solid colored insulation twisted together. For example, the blue pair includes one wire solid blue in color and a second wire white with blue stripes. The same is true for the green, orange, and brown pairs. In the 568B standard, the color coding standardizes the position each conductor occupies when assembled into an RJ45 modular connector or modular jack.
There are 8 positions in a modular connector, one for each conductor. A prior art RJ45 plug includes a front where it mates with a jack and a rear where the twisted pair cable enters the plug. The RJ45 plug includes a locking tab to releasably secure it to the jack. Viewing the front of the RJ45 plug, with the locking tab at the top, eight conductor positions are designated one through eight from left to right. Under the standard, the blue pair typically is designated Pair #1 and occupies positions 4 and 5 with the solid blue conductor in position 4 and the white/blue conductor in position 5. The Orange pair is designated Pair #2 and occupies positions 1 and 2 with the white/orange conductor in position 1 and the Orange conductor in position 2. The green pair is designated Pair #3 and is also known as the split pair in the RJ45 assembly because it occupies positions 3 and 6 with the solid green conductor in position 6 and the white/green color conductor occupying position 3. The brown pair is designated Pair #4 and occupies positions 7 and 8. The white/brown conductor is located in position 7 and the solid brown conductor in position 8. The importance of these standardized positions will become apparent in the description of the sub components and assembly of the new connector of the present invention.
The most dominant interface for connecting 4 pair twisted pair cable in the market at the time of this application is the RJ45 connector interface as described by the FCC in 47 CFR 68 Subpart F. The FCC standard describes dimensional tolerances for the plug, port and features to assure operable compatibility between plugs and jacks made by various manufacturers. Other RJ style connector interfaces also exist.
Typically an industry standard modular jack has one port for mating with an RJ45 plug, that meets the requirements of FCC under 47 CFR 68 Subpart F and a second port that is adapted to attach twisted pair cable conductors to the jack. Generally, jacks are terminated to twisted pair cable in the field by stripping back the outer insulating jacket, exposing the conductor pairs, and terminating the individual conductors of these pairs to terminals on the jack. Patch cords in predetermined lengths, with RJ45 plugs assembled to each end, are available to connect hardware such as computer work stations and printers to the modular jacks and thus to the network.
Typical RJ modular plug designs are used with cable made up of 4 twisted pairs and a plug assembly that attaches to the cable, making connection with the 4 pairs. The twisted pairs are identified as Pair 1, Pair 2, Pair 3, and Pair 4. There exists a wiring standard known as TIA/EIA 568-B T568B that assigns the blue/blue-white pair as pair 1, the orange/orange-white pair as Pair 2, the green/green-white pair as Pair 3, and the brown/brown-white pair as Pair 4.
At the connection interface end of the plug assembly there are a series of 8 slots that house blade contacts that make up the physical and electrical interface between the plug assembly and a jack with which the plug mates. This interface configuration is well known by those skilled in the technology and fully defined by an industry standard. To assure proper continuity of signal pairs through a structured cabling system, it is required that the cable pairs assume specified positions within the plug assembly. Slots in the plug are identified as slot or “Pin 1” sequentially to slot or “Pin 8” across the series of slots. The orange/orange-white (Pair 2) occupies slot positions 1 and 2, the green/green-white pair (Pair 3), also known as the split pair, occupies slot positions 3 and 6, the blue/blue-white (Pair 1) occupies slot positions 4 and 5, and the brown/brown-white (Pair 4) occupies the 7 and 8 slot positions.
The orange-white, green-white, blue-white, and brown-white are the striped conductors of the pair while the partnering conductor of the pair is a solid color (orange, green, blue, and brown). The striped colored conductors occupy the odd sequence of slots (1,3,5, and 7). The solid colored conductors occupy the even series of slots (2,4,6, and 8).
This nomenclature and practice is consistent within structured cable systems in the industry to assure signal integrity and continuity as well as interoperability between vendor products. There also exists a wiring standard know as TIA/EIA 568-B T568A that defines a different wire placement. The design described herein can apply to either standard T568A or T568B however for the purpose of description, only the T568B will be referred too.
In many cases, the modular connector is installed by craft personnel in the field. Problems are associated with installing jacks and plugs in the field related to inconsistency of method that occur from one installer to the next. These result is failures in data transmission and the expenditure of large amounts of time and effort to troubleshoot and repair inadequate field made connections.
Thus the network wiring industry would benefit from a network wiring termination system that would allow for pre-termination of conductors, testing of the network wiring components prior to release to field personnel and ease of pulling network wiring through conduit and past obstacles that are commonly encountered in the installation of network cabling.